/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/ViewModels/HierarchyEditor/NiagaraHierarchyViewModelBase.h
Hierarchy items reflect the already edited hierarchy. This should generally be constructed from persistent serialized data.
const [TArray](API\Runtime\Core\Containers\TArray)< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FNiagaraHierarchyItemViewModelBase](API\Plugins\NiagaraEditor\ViewModels\HierarchyEditor\FNiagaraHierarch-_6) > > & GetHierarchyItems() const